This study is exploring the combination of two drugs, MRX-2843 and Osimertinib, to treat advanced non-small cell lung cancer (NSCLC) with a specific gene mutation called EGFR. The EGFR gene helps cells grow and divide, and mutations can lead to uncontrolled cancer growth. The drugs aim to block enzymes that help cancer cells grow. Patients in this study will take the medications by mouth every day in 28-day cycles. The main goal is to find the best dose and understand any side effects.

• Participants will be in the study until their disease progresses or side effects become unacceptable.
• The study requires taking medicine daily and regular follow-up after treatment ends.
• Before joining, participants must have specific health conditions and agree to use birth control during the study.

Potential participants should ensure they meet specific health criteria, understand the study duration, and follow safety guidelines. The study involves regular check-ups and may require stopping other treatments. Participants are encouraged to consider potential risks and benefits and discuss with their doctors.